Keeping Engine Cool

[mrnickleye]

Hello out there in Supra Cyber World....I just wanted to pass along a few things to help you get-keep those Supras running cool. I just got mine all FINE again, and I LOVE to slide behind that wheel and GO. So...........

Radiator caps are cheap. Get a new one ! 1 lb of cap pressure = 3* of raised boiling point of coolant. Weak cap means boil overs !!

I run a mixture of coolant-water(distilled) at approx 65% coolant. It raises the boiling point, lowers the freeze point, and most of these newer namebrand coolants have additives that increase the absorption of heat. (Check the labels first)

Make sure your radiator is in good condition and clean. If you need one check around online. I got mine here (free shipping and got it next day) $120 http://www.autocoolradiators.com

By the way, the coolant always flows thru the heater core EXCEPT when the temp is set to 65*(lowest) on your heater/ac choice.

Thermostats are cheap, get a new one. It MUST be in place to slow the coolant flow thru the radiator so it will have time to cool. I live in the Mojave Desert. All summer (Mid-May to Mid-OCT) its 90-110*. I also go for drives in some very steep, hot mtns nearby.

I use a 180* stat, just to let it run a few degrees cooler when it can. The car's computer will go into 'closed-loop' (normal)operation at 160*, so no problem there. (The stat opening temperature is to get the coolant at a 'minimum' temp.) On a hot day an engine can run well over 200* anyway. I run a 195* stat in the cold desert winters for a better heater.

I always remove the toggle that is on most stats. I drill the hole to 4mm to let any trapped air bleed on thru to the radiator. This will NOT cause any problems with stat or engine operation. Be SURE to put the stat in correctly, with spring towards the engine, and the hole on top. Once, I had to raise the car and bleed air from the heater core when I put in a new radiator because I hadn't drilled the hole yet.
I did NOT have to do it last month when I put a new head gasket on. The heater core gurgled for 3-4 days, then purged itself. I believe the hole in the stat is why it purged.

These cars came with (but many are missing them) plastic mud shields mounted all under engine to help keep water and mud from entering the engine compartment. (Toyota puts them on everything). Another important reason to have at least the one from the front bumper to the frame directly under the radiator is...cooling ! Air coming in from the grill opening (bumper) needs to be forced into the radiator. Without this shield much of the air will pass on by under the car instead. (Just get down on all 4's and look straight on at it). I had to make my own (dealer wanted WAY too much $$) out of some sheet metal from the hardware store. I used existing bolts and some 1' fender washers.

ALWAYS leave the fan shroud on and use a GOOD fan clutch. The shroud makes the fan pull air thru the radiator, and not from the sides of the blades (the old "least path of resistance" rule). AT 80km/h & up, the fan is not normally doing much, that's why the clutch is there, to let it slip and not drag down the HPs. At slower speeds, traffic stops, and steep grades, the fan is all you have to keep it cool. An engine runs hottest going up a steep grade.

If you mod to an electric fan (as I have), be sure to get one that will flow at least 1800cfm. (You will remove the factory shroud for this change) http://store.summitracing.com/egnsearch.asp?N=400006

I'm using this one now. http://store.summitracing.com/partde...5&autoview=sku

I have the 2 optional factory A/C electric fans wired with an 'over-ride' switch (where one of the coin holders was) so I can turn them on when needed (like pulling a steep grade without the A/C on.

I also (hey, I live in the desert) put a large transmission cooler on the front of the radiator (after the condensor). http://store.summitracing.com/egnsea...=KeywordSearch

I tied in to the coolant system by removing the coolant bi-pass hose (small 7" long elbow under thermostat) and ran the hoses to the metal tubes. I looped the hoses (purchased $5 extra coolant hose instead of trans hose) around and under the air cleaner to reach the new cooler. I calculated a 45% increase in radiator capacity. (1 to 2 hr job) My gage sits just below 1/2 now. I NEVER run hot now. (I'll let you know about if that changes on my next hot day mtn. drive.)

I did remove the rubber strip that is at back of engine compartment, the one that seals the hood when its closed. This allows air to leave the engine compartment easier, thus letting more air pass thru the radiator. Just look at that compartment!! Its very full. The air must get pushed out. (Take a small bag and poke 5 pencil holes in the bottom. Now blow air into it. Next add 10 more holes into bottom. Blow. Easier on your lungs, huh? Same theory with engine compartments, freer flow thru radiator=cooler )

Also, I installed a small transmission cooler to the automatic trans lines .....http://store.summitracing.com/egnsea...=KeywordSearch
I used some metal brackets with multiple holes, down low in front of the condensor (approx. 6" out) . I ran the oil to this cooler FIRST so it would take some of the heat away BEFORE the oil gets to the radiator. The line going to the radiator on the left side(battery side) is the one to tie into.
Tranny will last MUCH longer with this cooler added.

I'm tired now......bye bye....and KEEP COOL people........